This topic describes how to use an image to create an NGINX application that is accessible over the Internet. You can use images to create stateless applications that are accessible from the Internet.

Procedure

  1. Log on to the ACK console.
  2. In the left-side navigation pane, click Clusters.
  3. On the Clusters page, click the name of a cluster or click Details in the Actions column. The details page of the cluster appears.
  4. In the left-side navigation pane, click Workload.
  5. On the Deployments tab, click Create from Image.
  6. On the Basic Information wizard page, configure the basic settings.
    Basic configuration
    Parameter Description
    Name The name of the application.
    Namespace The namespace where you want to deploy the application. The default namespace is automatically selected. You can select another namespace.
    Replicas The number of pods that are provisioned for the application.
    Type The type of the application. You can select Deployments, StatefulSets, Jobs, Cron Jobs, or DaemonSets.
    Label Add a label to the application. The label is used to identify the application.
    Annotations Add an annotation to the application.
    Synchronize Timezone Specify whether to synchronize the timezone from nodes to containers.
    Note Deployments is selected in this example. The default namespace is selected. You can select another namespace. The number of replicas equals the number of pods that are provisioned for the application.
  7. Click Next to proceed to the Container wizard page.
  8. Configure the containers.
    Note At the top of the Container wizard page, click Add Container to add more containers for the application.
    The following parameters are required to configure the containers.
    • GeneralGeneral settings
      Parameter Description
      Image Name Click Select Image. In the dialog box that appears, select an image and click OK. In this example, the NGINX image is selected.

      You can also enter the address of a private registry. The registry address must be in the domainname/namespace/imagename:tag format.

      Image Version

      • Click Select Image Version and select an image version. If you do not specify an image version, the latest image version is used.
      • You can select the following image pull policies:
        • ifNotPresent: If the image you want to pull is found in the region where the cluster is deployed, the local image is used. Otherwise, ACK pulls the image from the corresponding repository.
        • Always: ACK pulls the image from the repository each time the application is deployed or expanded.
        • Never: ACK uses only local images.
        Note If you select Image Pull Policy, no image pull policy is applied for the deployment of the application.
      • To pull the image without a secret, click Set Image Pull Secret to set a secret for pulling images. For more information, see Use aliyun-acr-credential-helper to pull images without a password.
      Resource Limit You can specify an upper limit for the CPU, memory, and ephemeral storage space that the container can consume. This prevents the container from occupying an excessive amount of resources. The CPU resource is measured in milicores (one thousandth of one core). The memory resource is measured in MiB. The ephemeral storage resource is measured in GiB.
      Required Resources The amount of CPU and memory resources that are reserved for this application. These resources are exclusive to the container. This prevents the application from becoming unavailable when other services or processes occupy these resources.
      Container Start Parameter
      • stdin: specifies that start parameters defined in the console are sent to the Linux system.
      • tty: specifies that start parameters defined in a virtual terminal are sent to the console.
      Privileged Container
      • If you select Privileged Container, privileged=true is set for the container and the privilege mode is enabled.
      • If you do not select Privileged Container, privileged=false is set for the container and the privilege mode is disabled.
      Init Container If you select Init Container, an init container is created. An init container provides tools for managing pods. For more information, see init Containers.
    • Optional:Ports
      Specify the container ports.
      • Name: Enter a name for a port.
      • Container Port: the container port that you want to open. Enter a port number from 1 to 65535.
      • Protocol: Select TCP or UDP.
    • Optional:Environments
      You can use key-value pairs to set environment variables for pods. Environment variables are used to apply pod configurations to containers. For more information, see Pod variables.
      • Type: the type of the environment variable. You can select Custom, ConfigMaps, Secret, Value/ValueFrom, or ResourceFieldRef. If you select ConfigMaps or Secret as the type of the environment variable, all values in the selected ConfigMaps or Secret are passed to the container environment variable. In this example, Secret is selected.

        Select Secret from the Name drop-down list and select a Secret from the Value/ValueFrom drop-down list. All values in the selected Secret are passed to the environment variable.

        In this case, the YAML file for deploying the application contains the settings that reference all values in the specified Secret.

      • Variable Key: Specify the key of the environment variable.
      • Value/ValueFrom: This reference is used to define the environment variable.
    • Optional:Health Check

      Health check settings include liveness and readiness probes. Liveness probes determine when to restart the container. Readiness probes indicate whether the container is ready to accept network traffic. For more information about health checks, see Configure Liveness, Readiness, and Startup Probes.

      Request type Description
      HTTP Sends an HTTP GET request to the container. You can set the following parameters:
      • Protocol: HTTP or HTTPS.
      • Path: the requested path on the server.
      • Port: the container port that you want to open. Enter a port number from 1 to 65535.
      • HTTP Header: the custom headers in the HTTP request. Duplicate headers are allowed. Key-value pairs are supported.
      • Initial Delay (s): the initialDelaySeconds field in the YAML file. This field specifies the wait time (in seconds) before the first probe is performed after the container is started. Default value: 3.
      • Period (s): the periodSeconds field in the YAML file. This field specifies the frequency (in seconds) that the probe is performed. Default value: 10. Minimum value: 1.
      • Timeout (s): the timeoutSeconds field in the YAML file. This field specifies the time (in seconds) after which the probe times out. Default value: 1. Minimum value: 1.
      • Healthy Threshold: the minimum number of consecutive successes that must occur before a container is considered healthy after a failed probe. Default value: 1. Minimum value: 1. For liveness probes, this parameter must be set to 1.
      • Unhealthy Threshold: The minimum number of consecutive failures that must occur before a container is considered unhealthy after a success. Default value: 3. Minimum value: 1.
      TCP Sends a TCP socket to the container. Kubelet attempts to open the socket on the specified port. If the connection can be established, the container is considered healthy. Otherwise, the container is considered unhealthy. Supported parameters include:
      • Port: the container port that you want to open. Enter a port number that ranges from 1 to 65535.
      • Initial Delay (s): the initialDelaySeconds field in the YAML file. This field specifies the wait time (in seconds) before the first probe is performed after the container is started. Default value: 15.
      • Period (s): the periodSeconds field in the YAML file. This field specifies the frequency (in seconds) that the probe is performed. Default value: 10. Minimum value: 1.
      • Timeout (s): the timeoutSeconds field in the YAML file. This field specifies the time (in seconds) after which the probe times out. Default value: 1. Minimum value: 1.
      • Healthy Threshold: the minimum number of consecutive successes that must occur before a container is considered healthy after a failed probe. Default value: 1. Minimum value: 1. For liveness probes, this parameter must be set to 1.
      • Unhealthy Threshold: The minimum number of consecutive failures that must occur before a container is considered unhealthy after a success. Default value: 3. Minimum value: 1.
      Command Runs a probe command in the container to check the health status of the container. Supported parameters include:
      • Command: the probe command that is run to check the health status of the container.
      • Initial Delay (s): the initialDelaySeconds field in the YAML file. This field specifies the time (in seconds) to wait before the first probe is performed after the container is started. Default value: 5.
      • Period (s): the periodSeconds field in the YAML file. This field specifies the frequency (in seconds) that the probe is performed. Default value: 10. Minimum value: 1.
      • Timeout (s): the timeoutSeconds field in the YAML file. This field specifies the time (in seconds) after which the probe times out. Default value: 1. Minimum value: 1.
      • Healthy Threshold: the minimum number of consecutive successes that must occur before a container is considered healthy after a failed probe. Default value: 1. Minimum value: 1. For liveness probes, this parameter must be set to 1.
      • Unhealthy Threshold: The minimum number of consecutive failures that must occur before a container is considered unhealthy after a success. Default value: 3. Minimum value: 1.
    • Lifecycle

      You can set the following parameters to configure the lifecycle of the container: Start, Post Start, and Pre Stop. For more information, see Configure the lifecycle of a container.

      • Start: Set the command and parameter that take effect before the container starts.
      • Post Start: Set the command that takes effect after the container starts.
      • Pre Stop: Set the command that takes effect before the container stops.
    • Optional:Volume
      You can mount local storage volumes and persistent volume claims (PVCs) to the container.
      • Local Storage: You can select HostPath, ConfigMap, Secret, and EmptyDir. The source directory or file is mounted to a path in the container. For more information, see Volumes.
      • PVC: Select Cloud Storage.
      In this example, a PVC named disk-ssd is mounted to the /tmp path of the container.Configure the volume
    • Optional:Log
      Configure Log Service. You can specify collection configurations and custom tags.
      Notice Make sure that the Log Service agent has been installed for the cluster.
      Parameter Description
      Collection Configuration Logstore: Create a Logstore in Log Service to store collected logs.
      Log Path in Container: Specify stdout or a path to collect logs.
      • stdout: specifies that the stdout files are collected.
      • Text Logs: specifies that logs in the specified path of the container are collected. In this example, /var/log/nginx is specified as the path. Wildcard characters can be used in the path.
      Custom Tag You can also set custom tags. Custom tags are added to the logs of the container when the logs are collected. Custom tags provide an easy method to filter collected logs and perform statistical analytics.
  9. Set the preceding parameters based on your business requirements and click Next.
  10. Optional:Configure advanced settings.
    • Access Control
      Note

      You can configure the following access control settings based on your business requirements:

      • Internal applications: For applications that run inside the cluster, you can create a service of the ClusterIP or NodePort type to enable internal communication.
      • External applications: For applications that are open to the Internet, you can configure the access control by using one of the following methods:
        • Create a service of the LoadBalancer type and enable access to your application over the Internet by using a Server Load Balancer (SLB) instance.
        • Create an Ingress to route external access to a service inside the cluster. For more information, see Ingress.

      Configure the access control settings to enable access to pods that run the application. In this example, a ClusterIP service and an Ingress are created to enable access to the NGINX application over the Internet.

      Parameter Description
      Services Click Create on the right side of Services. In the Create Service dialog box, set the parameters. For more information about the parameters that are required to create a service, see Create a service. ClusterIP is selected in this example.
      Ingresses Click Create on the right side of Ingresses. In the Create dialog box, set the parameters. For more information about the parameters that are required to create an Ingress, see Ingress configurations.
      Note When you deploy an application from an image, you can create an Ingress for only one service. In this example, a virtual hostname is specified as the test domain name. You must add a mapping rule for this domain name to the hosts file, as shown in the following code block. In actual scenarios, use a domain name that has obtained an Internet Content Provider (ICP) number.
      101.37.224.146   foo.bar.com    #The IP address of the Ingress.

      You can find the created service and Ingress in the Access Control section. Click Update or Delete to modify the settings.

    • Scaling
      Specify whether to enable HPA to automatically scale the number of pods based on the CPU and memory usage. This enables the application to run smoothly at different load levels.
      Note To enable Horizontal Pod Autoscaler (HPA), you must configure resources that support scaling for the container. Otherwise, HPA does not take effect.
      • Metric: Select CPU Usage or Memory Usage. The selected resource type must be the same as the one you have specified in the Required Resources field.
      • Condition: Specify the resource usage threshold. HPA triggers scaling events when the threshold is exceeded.
      • Max. Replicas: Specify the maximum number of replicated pods to which the application can be scaled.
      • Min. Replicas: Specify the minimum number of replicated pods that must run.
    • Scheduling
      You can set the following parameters: Update Method, Node Affinity, Pod Affinity, Pod Anti Affinity, and Toleration. For more information, see Affinity and anti-affinity.
      Note Node affinity and pod affinity affect pod scheduling based on node labels and pod labels. You can add node labels and pod labels that are provided by Kubernetes to configure node affinity and pod affinity. You can also add custom labels to nodes and pods, and then configure node affinity and pod affinity based on these custom labels.
      Parameter Description
      Update Method

      Select Rolling Update or OnDelete. For more information, see Deployments.

      Node Affinity Add labels to worker nodes to set Node Affinity.
      Node Affinity supports required and preferred rules, and various operators, such as In, NotIn, Exists, DoesNotExist, Gt, and Lt.
      • Required: Specify node labels that must be matched for pod scheduling. In the YAML file, these rules are defined by the requiredDuringSchedulingIgnoredDuringExecution field of the nodeAffinity parameter. These rules have the same effect as the NodeSelector parameter. In this example, pods can be scheduled to only nodes with specified labels. You can create multiple required rules. However, only one of them must be met.
      • Preferred: Specify the node weight and node labels that are not required to be matched for pod scheduling. Pods are scheduled to a node that matches the preferred rules when multiple nodes match the required rules. In the YAML file, these rules are defined by the preferredDuringSchedulingIgnoredDuringExecution field of the nodeAffinity parameter. In this example, the scheduler attempts to schedule the pod to a node that matches the preferred rules. You can set node weights in preferred rules. If multiple nodes match the required and preferred rules, the node with the highest weight is preferred for pod scheduling. You can create multiple preferred rules. However, all of them must be met before the pod can be scheduled.
      Pod Affinity Pod affinity specifies that pods can be scheduled to nodes or topological domains where pods with matching labels are deployed. For example, you can use pod affinity to deploy services that communicate with each other to the same topology domain, such as a host. This reduces the network latency between these services.
      Pod affinity enables you to specify to which node pods can be scheduled based on the labels on other running pods. Pod affinity supports required and preferred rules, and the following operators: In, NotIn, Exists, and DoesNotExist.
      • Required: Specify rules that must be matched for pod scheduling. In the YAML file, these rules are defined by the requiredDuringSchedulingIgnoredDuringExecution field of the podAffinity parameter. A node must match the required rules before pods can be scheduled to the node.
        • Namespace: Specify the namespace to apply the required rule. Pod affinity rules are defined based on the labels that are added to pods and therefore must be scoped to a namespace.
        • Topological Domain: Set the topologyKey. This specifies the key for the node label that the system uses to denote the topology domain. For example, if you set the parameter tokubernetes.io/hostname, topologies are determined by nodes. If you set the parameter to beta.kubernetes.io/os, topologies are determined by the operating systems of nodes.
        • Selector: Click Add to add pod labels.
        • View Applications: Click View Applications and set the namespace and application in the dialog box that appears. You can view the pod labels on the selected application and add the labels as selectors.
        • Required Rules: Specify labels on existing applications, the operator, and the label value. In this example, the required rule specifies that the application to be created is scheduled to a host that runs applications with the app:nginx label.
      • Preferred: Specify rules that are not required to be matched for pod scheduling. In the YAML file, preferred rules are defined by the preferredDuringSchedulingIgnoredDuringExecution field of the podAffinity parameter. The scheduler attempts to schedule the pod to a node that matches the preferred rules. You can set node weights in preferred rules. Set the other parameters as described in the preceding settings.
        Note Weight: Set the weight of a preferred rule to a value from 1 to 100. The scheduler calculates the weight of each node that meets the preferred rule based on an algorithm, and then schedules the pod to the node with the highest weight.
      Pod Anti Affinity
      Pod anti-affinity rules specify that pods are not scheduled to topology domains where pods with matching labels are deployed. Pod anti-affinity rules apply to the following scenarios:
      • Schedule the pods of an application to different topology domains, such as multiple hosts. This allows you to enhance the stability of the service.
      • Grant a pod exclusive access to a node. This enables resource isolation and ensures that no other pod can share the resources of the specified node.
      • Schedule pods of an application to different hosts if the pods may interfere with each other.
      Note The parameters of pod anti-affinity rules are the same as those of pod affinity rules. You can create the rules for different scenarios.
      Toleration Set toleration rules to allow pods to be scheduled to nodes with matching taints.
      Schedule to Virtual Nodes Specify whether to schedule pods to virtual nodes. This option is unavailable if the cluster does not contain a virtual node.
    • Labels and Annotations
      • Pod Labels: Add a label to the pod. The label is used to identify the application.
      • Pod Annotations: Add an annotation to the pod.
  11. Click Create.
  12. After the application is created, you are redirected to the Complete page. You can find the resource objects under the application and click View Details to view application details.
    View details

    After you submit the request, you are redirected to the nginx-deployment details page.

    Note You can also perform the following steps to create Ingresses and Services: In the Access Control section:
  13. Return to the details page of the cluster. In the left-side navigation pane, click Ingresses. You can find the created Ingress on the Ingresses page.
    Ingress rules
  14. Enter the test domain name in the address bar of your browser and press Enter. The NGINX welcome page appears.
    NGINX welcome page